technical specification for 415v lt switchboards

7/26/2019 Technical Specification for 415v Lt Switchboards

http://slidepdf.com/reader/full/technical-specification-for-415v-lt-switchboards 1/32

TECHNICAL SPECIFICATION

FOR

415V LT SWITCHBOARD



1 CODES AND STANDARDS

The design, material, construction, manufacture, inspection, testing and performance of the

LT switchboards shall comply with all currently applicable statutes, regulations and safety

codes.

The LT switchboards and its components s hall conform to the latest applicable

standards

Specified below.

In case of conflict

between

the standards

and this

Specification, this specification shall govern.

Circuit Breaker : BS: 3659 / IEC: 56, 694 /IS: 2516

Switchboard General Requirements

:

BS: 5486 / IEC: 947 / IS 13947

Factory Built Assemblies of SWGR and

Control gear for Voltages up to and including

1000 V AC & 1200 V DC

:

BS: 5486 / IEC: 439 / IS: 8623

Electrical Relays for Power System

:

BS: 142 / IEC: 255 / IS: 3231

Protection

Air Break Switches, Motor Protection : BS: 60947 / IEC: 947 –2 & 3 /IS:

Circuit Breaker

1

3947

Bus-Bar supports Insulators : BS: 3297 / IEC: 273, 168 / IS: 2544

Low voltage Fuses : BS: 1362 / IEC: 269-1 / IS: 13703

Contactors : BS: 60947 -4 / IEC: 947-1/

IS: 13947

Control Transformers for switchgear and

Control gear voltage not exceeding

:

IS 12021

Starters

:

BS: 60947-4 / IEC: 292-14/

IS: 13947

Current Transformers : BS: 7626 / IS: 2705

Voltage Transformers

:

BS: 7625 / IEC: 44, 186 /IS: 3156

Indicating Instruments

:

BS: 89 / IEC: 51 /IS: 1248

Marking and identification of conductor

And Apparatus Terminals

:

BS: 159 / IS: 11353

A.C. Electricity Meters : BS: 5685/IEC: 145,211/

IS: 722, 8530



Degree of Protection : BS: 60529/IEC: 947-PI/IS: 13947

Guide for marking of insulated conductor : IS: 5578

Guide for uniform system of marking and

Identification of conductors and apparatus : IS: 11353

Terminals

Selection, installation and maintenance of

:

IS: 10118

Switchgear and control gear

Code of practice for phosphating Iron and

Steel

:

BS: 3189 / IS: 6005

Phosphate treatment of iron and steel for

Protection against corrosion : IS: 3618

Specification for copper rods and bars for

Electrical purposes : IS: 613

Material data for Aluminum Bus-Bars : IS: 5082

2 AUXILIARY SUPPLIES

Following auxiliary supplies with +10% to -15% voltage variation, + 4% to -6% frequency

variations and +10% combined voltage and frequency variation are available:

Three (3) phase, 415V, Four (4) wire, 50 Hertz, effectively earthed AC supply.

220V ungrounded DC supply.

3. EQUIPMENT AND SERVICE REQUIRED

415V LT PCC, MCC, DBs as per Main SLD.

20% fully equipped spare feeder for each rating/each module shall be consider in each

PCC/MCC/ DBs.

LT switchgears are having two incomer with one bus coupler, the necessary interlocks will be

provided such that only two breakers/switch fuse units can remain closed at any given time.

The base channel frame of the switchgear/MCC/DB with hardware

Set of minimum accessories as detailed below:

i) Breaker lifting & handling truck

ii) Device for slow closing & opening of breaker

iii) Breaker racking in/out handle



Mandatory Spare parts

5. TECHNICAL REQUIREMENTS FOR L.T SWGR

The switchgear shall be formed using distinct vertical sections each comprising the following

compartments:

A completely metal enclosed horizontal busbar compartment running horizontally at

top.

Individual feeder modules organized in multitier mode.

Completely enclosed vertical bus bars serving all feeder modules in the vertical section.

Cable termination compartment.

Perforated sheet steel/insulating material enclosed horizontal auxiliary bus way for

control, interlock, indication and metering wiring running horizontally.

The 415V switchboard shall comprise air circuit breakers & s hall be metal clad, indoor

type floor mounted (in fully Draw out execution).Switchboard shall be in single tier

Execution for incomers & bus couplers & two tiers for outgoing feeders.

Relative position of incomers shall be as per the equipment layout requirement.

Circuit breaker shall be mounted on fully draw out truck with service, test and isolated

positions and complete with following safety interlocks and safety shutters with padlock

facility:

It shall not be possible to move the truck in or out of cubicle when the breaker is closed.

CB compartment door shall be mechanically interlocked so that it will not be possible to

close the CB in plug position when the door is open.

It shall not be possible to push the truck in close position if either of the safety shutter is

not free and not in close position.

The position of various control s witches, pu sh button s, levers etc. requiring manual operation,shall be at a height not less than 450mm and shall not exceed 1850mm from

The finished floor level.

Name plate for each incoming bus coupler, and outgoing feeder at front and back, both on

the fixed portion of the panel.

All panels shall have space heater with switch and cubicle illumination lamp with door



switch

All breakers of similar rating shall be interchangeable.

Metal sheets shall be provided between two adjacent vertical panels running to the full width

of the wider panel and upto full useful height of the switchgear.

The front of the board shall comprise of individually enclosed Air Break Circuit Breakers,

starters, Fuse switch and switch fuse modules.

All auxiliary devices for control, indication, measurement and protection such as control

and se lector switches, indicating lamp s, a mmeters, voltmeters, e nergy meters, protective relays

shall be mounted on the front side of the respective compartment only.

The design shall be such that unless required for maintenance/inspection purpose, all power

on/off or start/stop and relay reset operations shall be performed without opening the panel

door.

Rated short time withstand current not less than the system short circuit level specified for

1sec. Rated peak withstand current not less than 2.1 times the system short circuit level.

Derating of Equipment The current rating of all equipment specified in the Bill of Material are

the minimum standard current ratings required at a reference ambient temperature of 50°C.

The Bidder shall indicate clearly the derating factors employed for each component and furnish

the basis for arriving at the se derating f actors duly considering the specified current rating and

ambient temperature of 50°C.

6. CONSTRUCTIONAL DETAILS FOR L.T SWGR

The complete board shall be of coordinated design so that shipping groups of the board

are easily assembled together at site into a continuous lineup . Necessary standard connecting

material shall be supplied.

Name plates of elegant and durable design and quality shall be fixed to the individual

compartments, feeder modules etc.

The boards covered by this

enquiry s hall

be designed, manufactured an d tested in

accordance with the latest revisions of the relevant applicable standards listed

elsewhere in this document.

The framework of the boards shall be constructed of preformed steel channels, angles

and side sheets bolted together and suitably reinforced to form a rigid, self-supporting,

Compact assembly to function properly under both normal and short circuit conditions.



The bus compartments shall comprise of one main horizontal TPN bus unit with vertical

risers for connection to the individual modules.

The board shall be of totally metal enclosed ventilated multiple unit construction. End

units shall include provisions for future main bus extensions and installation of additional

units on either side with the framework suitably drilled to receive the additional modules

and the bus bars fitted with fish plates and associated hardware enabling future

Extension without involving major fabrication works on the panel in service.

Functional units when working on those of adjacent un its. These barriers s hall have insulating

inserts as necessary for taking the interconnections etc.

Doors and covers shall be of sheet steel of thickness not less than 2.0 mm cold rolled and the

edges shall be reinforced against distortion by rolling/bending/ or by addition of

welded reinforcement member s. The doors shall have concealed type of hinges. Wherever the door

length is more than 600 mm, necessary stiffeners shall be provided.

Cut outs shall be true in shape and free from sharp edges.

The panel shall be provided with integral metal base channel 7 5 mm in height for

Facilitating grouting on the floor.

Dust excluding gaskets of neoprene shall be used on all doors to ensure dust tightness

of the interior while the board is in service. Suitable ventilating louvers designed in such

a way as to prevent entry of falling dust shall be provided at the sides and top so that a

Free circulation of air through the equipment under thermal cycling conditions is ensured.

The louvers shall be provided with fine-screened brass meshes to prevent entry of

Vermin. If ventilation

louvers are provided on top, suitable canopy / cover

shall

be

Provided, with wire mesh inside the panel.

The hardware‟s shall be zinc plated & passivized; these shall be of the captive type to obviate loss

of these bolts / s crews etc., when the doors / covers are opened for servicing / inspection.

Cold Rolled Sheet Steel of 2.5 mm. thickness shall be used for all members, other than doors

and covers.

All c components including the busbars s hall be capable of being re moved from fro nt.

The cable alleys shall also be at the front of the board for MCCs. However, cable access

may be arranged at the rear side for ACB feeders.

All the doors for the feeder modules in the front shall have individual sheet steel hinged

doors with concealed hinges. These doors shall be capable of being physically lifted off

the main base s hell an d fixed back in position while the panel is i n service without

necessitating removal of any screws or welding etc. and with the adjacent modules in

service with their doors closed. The doors shall also have interlock facility, with defeat



provision, to ensure that the door is not opened when feeder is in ON position.

The bus bar chamber shall have screwed covers at the front, on the sides and on the top.

The panels shall be suitable for cable entry at bottom. Undrilled, removable gland plates

Shall be provided at the bottom for the switchboards to suit entry of the cables as furnished in

the schedules. Cable clamping arrangements shall be provided in the cable

Alley.

The switchboards shall have uniform height of not more than 2 350 mm. The height of

the operating handle for the feeder modules, indicating lamps, instrument fuses etc., in

the topmost tier which may need adjustment / replacement shall all be not more than

1850 mm from the finished operating level on the floor s o that these a re easily

accessible for the operating / maintenance personnel without having to take recourse to

ladders / steps etc.,

The minimum operating height of the switch handles shall not be less than 450 mm from

the finished floor level including the safety rubber mat.

All live parts shall be suitably shrouded with non-deteriorating Insulating barriers so as to

prevent any accidental contact with these b y the operating / maintenance personnel

while the panel is in service and the modules are opened for inspection / servicing etc.,

7. BUSBARS

The bus bars shall be of hard drawn high conductivity electrolytic grade ( 63401 W P)

Aluminum conforming to IS: 5082. The bus bars shall be of uniform cross section along

its entire length. No tapering of the bus bar cross section is allowed.

Horizontal and vertical bus bars shall be provided with PVC sleeves of high quality.

The joints in the bus bars s hall be of the bolted ty pe and its hall be ensured that the

following precautions are observed:



The contact pressure must be ample and this shall be maintained during the time the

panel is in service.

The surfaces of the conductors must be clean.

With flat conductors, the overlap should be equal to or greater than the width of the

bars or ten times the bar thickness whichever is greater.

The joints shall be treated by the application of joint compound to render the joint

moisture-proof

For the joints, use bolts of cadmium plated high tension MS bolts and nuts.

All the bus bar joints / bolts should be silver plated for rating 1600 Amps and above and

shrouded with proper insulated material. The efficiency of the joints shall be preserved by

smearing the surfaces with oxide inhibiting grease just prior to making the joint.

The neutral bus shall be rated for the full short circuit current. Rating of horizontal buses

shall be same as that of incomer circuit breakers and vertical run shall be same as that of

outgoing breaker rating.

The switchboard shall be provided with power busbars for the 3 phases and neutral. The

Busbars fed by the incomer s hall r un continuously throughout the length of the switchboard.

The busbars shall have a short circuit withstand capacity of 50 kA for 1 Sec.

The busbars shall be phase identified by colour, throughout the length or identification ofbusbars at regular intervals. Colour code shall be RED, YELLOW and BLUE for phase

buses and BLACK for the neutral. Busbars shall be rated for 40° C temperature rise over

an ambient of 50° C.

The cross section of the bus bars s hall be uniform throughout after considering all

derating factor for PCC and MCCs.

Busbars shall be supported on tough, non-hygroscopic, resin bonded self-extinguishing

fire retardant insulators of SMC / D MC with ribbed construction to prevent tracking due

to dust

accumulation an d

to have larger

c reepage

path s.

All

the phases shall

be

Individually supported. I f a Common support is provided f or all the three phases, anti

tracking

barriers s hall

be

Incorporated. B usbars

and supports

shall

withstand t he

Maximum stresses that are likely to be induced by the short circuit currents specified.



The necessary calculation for selecting size of bus bar and insulator shall be furnished

during detailed engineering for owner‟s approval.

All busbar joints s hall be Of the bolted type. Ring washers shall be used for joints to

Prevent loosening of the nuts and overheating. Lock nuts shall be incorporated for the

bolts besides the main nuts. The bolts and nuts used in the current carrying paths shall

all be of steel cadmium plated and the hardware s hall have adequate cover of the

protective cadmium coating to obviate corrosion while

the board

is in service. P roper

work space is required for tightening and checking the bolts and joints.

The bus bar

chambers

at the top s hall be to

tally

segregated from the rest o f

compartments

and rendered totally inaccessible under

Normal circumstances. No

Equipment / Instrument shall be mounted on the busbar chamber.

Power shall be distributed to each module or compartment by a set of vertical busbars.

The vertical busbars shall run behind the modules.

All bu sbars s hall be PVC sleeved and adequately shrouded to prevent accidental contact. The

sleeve used shall be of the heat shrinks type.

The bus bars shall run horizontally in a separate enclosure but may run in an enclosure

located within the power busbar compartment.

Necessary tee off connectors shall be used for distributing auxiliary supply to e ach vertical

panel. Rubber grommets shall be used for all wire entries to make the entries dust and

vermin proof.

8.

EQUIPMENT AND SERVICE DETAILS

All 415V/240V AC an d 220 V DC loads of Main plant as well as BOP is to be catered

From the LT switchgears/MCCS/ DBs included under this specification. While tentative

feeder requirements are indicated, Bidder is to prepare feeder lists for BOP systems in

his scope and provide required PMCCs/PCCs/MCCs/DBs to cater for all the required LT

Loads. Bidder to s elect p roper equipment rating and substantiate the same

by proper

Justification / calculation during detailed engineering. The equipment shall be supplied

as per the final requirement.



Certain switchgears with very long lengths s hall be sectionalized and physically separated for

ease of operation and maintenance. Interconnection of s uch sections by segregated phase bus-

ducts shall be in Bidder‟s scope. Successful Bidder shall furnish preferred arrangement based on

general arrangement drawing.

In certain cases, switchgear may have to be arranged in L, C or U shape. Bidder shall

provide dummy panels required for such arrangements and also for floor beam crossing.

This being a lump sum turnkey contract. No additional payments will be applicable for all

such requirements.

415V switchgears s hall have spring charged A.C. Mo tor operated stored energy type

Circuit breakers with integral manual spring charging handle. These breakers s hall be

electrically operated type and shall be provided with electrical and mechanical interlocks

to prevent paralleling of two different sources of supply.

All MCCs shall be of single front construction depending upon the space availability. All

Switchgears/MCCs shall b e Sectionalized. These shall be electrically Interlocked.

Provision s hall be

made

to

defeat interlock to enable

parallel

operation

i n case o f

Emergency.

The contractor shall furnish relay application checks / calculations to check adequacy of

the CTs / VTs as well as suitability of relay settings / setting ranges p roposed by the

Bidder. These checks / calculations shall be furnished during details engineering stage

for each and every feeder.

9. MODULE DESCRIPTION

The Bidder shall supply all the material as required for completing the schemes. It may

be c learly noted t hat t he bidder s hall offer A CBs, switches & c ontactors f or s tarters

covering the whole range upto 200 KW motor size in not more than six (6) sizes. Bidder

to select p roper eq uipment ra ting an d s ubstantiate th e same by p roper jus tification /

calculation. Sufficient s pace in each mo dule s hall be p rovided for r epair a nd

maintenance work. Components i.e. contactors O/L relays, MCBs, MCCBs, PBs etc., to

be used in v arious Switchgears / MCCs should be of reputed make duly

approved by

Owner / Consultant.

All moto r

f eeders ra ted b elow

30kW

will

be provided

with MCCB

/

MPCB, Pow er

Contactor & motor controller. Motor rated from 90 KW to 30kW shall be provided with

MCCB/MPCB unit, power contactor, motor controller with soft starter and DOL byp ass

etc., as per the requirement. The combination shall ensure type II coordination as per IS:



13947. Motors ra ted 90 K W a nd ab ove feeders t o be pr ovided with ACB s along with

protection re lays. All mo tor feeder mo dules s hall also be pr ovided w ith local / field /

remote selector switches on the module itself.

In all modules at least 2 NO + 2 NC spare contacts of main contactor shall be wired up to

the terminal block.

Each modu le shall have inde pendent

control

s upply trans former

of

415/240 V

and

suitable

c apacity

a nd protection at primary

and

s econdary s ide to be

pr ovided.

All

modules should have three distinct positions – service / Test / Isolated.

Drawout type control module shall have self-aligning power/ control disconnects. All

disconnects shall be silver plated to ensure good contacts.

The

module

shall hav e s ervice,

test

and w ithdrawn p ositions. Adequate

s liding

contacts shall be provided in the control circuit to provide for all interlocks, start/stop

commands, control supplies and power supplies, etc.

The

design s hall be such as to p ermit eas y withdrawal/reinsertion

of the un it

with

guide rails to ensure correct alignment.

Control Module shall house the control components for a circuit such as switch,

fuse, contactors, relays, push buttons, lamps etc.

The equipment lay out sha ll provide s ufficient w orking s pace in b etween t he components

and subject to Owner's approval.

Various mo dule/compartment size s sh all be multip le of one ba sic u nit to fa cilitate

modifications at site. Suitable provision for this purpose should also be incorporated

in the vertical bus bars.

Drawout ty pe c ontrol m odules of s ame s ize and t ype s hall be electrically and physically

interchangeable.

10. PANEL BOARDS

LT s witchgear and PCC/MCC boards shall be of fu lly dra wout mo dular c onstruction.

ACDB / DCD B shall be of draw out type module. The switchgear shall comprise floor-

mounted, self supporting with ISMC bas e frames or in-built kick plate of 75mm height,

dust tight sheet steel panels, with individual door for

each module. Main busbars shall

be accommodated in a horizontal busbar chamber running the full length of the board at

the top along with the neutral. The VBB will comprise of 3 phas e busbars in a busbar

chamber an d o ne neutral b us ba r and tes ted for

50 KA f ault le vel. C able alleys o f

adequate size (but not less than 250 mm) shall be provided in e ach vertical section for



ease of cable termination. Various feeders shall be arranged in individual compartments.

All feeders shall be wired out to th e terminals. Power cables connecting SS nuts bolts

and necessary cable supports in cable alley shall also be provided. Design shall be fully

compartmentalized an d m odular ty pe as c ommonly used for Motor Control Centres.

Extension

bus links properly s paced fo r termin ating

single c ables of size 120 s q. mm

and above as well as for terminating multiple cables of all sizes Where more than one

cable h ave t o be t erminated per unit, th e arrangement s hall permit c onnection and

disconnection

of

i ndividual c ables

s eparately

without d isturbing

other

c ables.Itsh all

conform to all applicable construction features specified herein for Switchgears / MCCs.

The panel boards shall be suitable for single front construction, floor mounting withfully

drawout design.

All AC and DC distribution boards and cabinets shall be complete with necessary neutral

links, earth bus, terminals, name plates, cable sockets, wiring, AC and DC distribution

boards shall have all s witches on front s ide of panels, operable from outside. Doors of

distribution boards and cabinets shall be lockable.

11. INDICATION LAMPS

These shall be of bunched LED type. The lamps shall have red, blue, green, amber and

white caps as specified.

All Indicating lamps s hall be c luster LED typ e with removable c over and s hould have

LVGP protection.

Electrical indications with colours as given below shall also be provided.

a) Breaker 'ON' - Red Lamp

b)

Breaker 'OFF'

-

Green Lamp

c) Breaker 'Auto Trip' - Amber Lamp

d)

Trip circuit healthy

-

White Lamp

e) Spring Charged - Blue

f)

Service Position

-

Amber

12. EARTHING CONNECTIONS

The panel shall be connected to an earth busbar running throughout the length of the

switchboard. The mi nimum ear th bus s ize s hall be 50x6 mm copper. A ll doors an dmovable parts shall be c onnected to the earth bu s w ith flexible c opper connections.

Provision shall be made to connect the earthing busbar to the p lant earthing grid at two ends.

All non-current carrying metallic parts of the mounted equipment shall be earthed.



With dr awable un its pro vided with self-aligning, spring loa ded, silver plated c opper

scrapping earth contacts of make before/break after type ensuring earth continuity from

service to the test position. Hinged doors earthed through flexible earthing braid.

13. CIRCUIT BREAKERS

The

b reakers

shall be of th ree pole

type, unles s

otherwise

s pecifically men tioned

elsewhere (4 pole in case of DG power incomer) and all the breakers shall be of draw-

out type.

The

operating

me chanism s hall

be of

motor operated s pring

c harged type unl ess

otherwise s pecifically men tioned, where it s hall b e of manual wound s pring c harged

type.

The circuit breakers shall be provided with mechanically operated emergency tripping /

closing device. This device shall be available on the front of the panel.

All circuit breaker shall be microprocessor based intelligent type direct acting O/C, S/C

& E/F release with measurement control & data transfer facility.

The release unit of bre akers (incomers, bus coupler & outgoing) shall have the facility for

taking input from a separately mounted NCT for earth fault protection.

The operating range of shunt trip coils of all breakers shall be minimum from 55-110%

(126-253V ac) of the rated 230V ac voltage. This is for reliable operation of the shunt trip

during single phase to ground fault on any phase.

The circuit breakers shall be provided with 6 NO + 6 NC minimum, convertible from NO to

NC and v ice versa at site. The spare auxiliary contacts shall be wired and available for f

uture us e. If spare auxiliary co ntacts are not available, lock-out relay of approved make &

type shall be used to multiply the available spare auxiliary contact.

Circuit Breaker positions shall be indicated electrically. The following indicating colours

shall be used.

Breaker 'Close' … Red

Breaker 'Open' … Green

Breaker 'Auto Trip' … AmberBreaker in service … Clear

Trip circuit healthy … Blue

Breaker Spring “Charged” … White



Circuit Breaker positions (Open & Close), location (service and test) and spring charged

conditions shall also be indicated mechanically.

The breakers s hall b e trip free. If av ailable a s a m anufacturer‟s s tandard f eature, the

breakers shall be provided with a release to trip the breakers instantaneously if closed on to

a fault.

The circuit breakers shall be provided with an antipumping feature. If an electrical relay

is us ed f or t his f eature, t he relay s hall be l ocated on the breaker c hassis. Th e anti

pumping feature shall be maintained even if the bus voltage disappears during a fault.

Circuit breaker trip and closing coils shall be rated for satisfactory operation under the

following conditions of supply voltage variation.

Trip coil: 55% to 110% of rated voltage

Closing coil: 85% to 110% of rated voltage.

Rated coil voltage shall be 220V DC

13.1 CIRCUIT BREAKER COMPARTMENTS

The ci rcuit breaker co mpartment sh all be fu lly draw o ut, tha t is, bus sid e & outgoing

power and control connections shall be through drawout contacts (it shall be possible to

drawout the withdraw able troll ey without h aving to unbolt or un screw any po wer and

control connections). Suitable guides shall beprovided to facilitate easy withdrawal of

the trolley. All identical feeder compartments shall be interchangeable without having to

carryout modifications.

Spring actuated and gravity operated safety shutters shall be provided for isolating the

busbars and other live parts when the breaker is completely withdrawn. The design of

compartment shall be such as to prevent movement of vermin from a pa rticular circuit

breaker compartment to any other portion of the panel when the b reaker is withdrawn



The earth connection shall remain connected in “test” and “service'” positions also.

The draw-out compartments shall have the following features and interlocks:

Compartment doors shall be interlocked against opening when breaker is in closed

or ON condition. However, it shall be possible to bypass this interlock for inspection

purposes.

It shall not be possible to push 'in' a drawn out circuit breaker in closed condition or

withdraw a circuit breaker in closed condition.

It shall

be p ossible to

operate a c ircuit b reaker only in the d efined " Full In" or

"Service" and "test" position inside the panel. It shall not be possible to operate the

breaker in in termediate position while inserting or withdrawing a cir cuit breaker or

while in "Full out”, position inside the Panel.

Castell

key

type in terlocks

shall b e p rovided b etween

fe eders, w herever specified.

Electrical interlocks shall also be deviced, wherever specified.

13.2 OPERATING MECHANISM

Electrical p ower operating me chanism shall be motor w ound s pring c harged s tored

energy type . How ever, manu al o perating me chanism ma y be o f

the s pring c harging

stored

energy type or the s pring assisted t ype. Prov ision s hall

be m ade f or manual

spring charging also. Closing time of circuit breakers with manual operating mechanism

shall be independent of the speed of the operating handle.

All stored energy operating mechanisms shall be equipped with following features:

Failure o f springs, v ibrations or shocks shall n ot c ause u nintended op eration o f

breaker or prevent intended tripping operation.



Closing of circuit breaker shall be prevented unless the spring is fully charged.

All electrical

power

operating mechanisms s hall be s uitable for remote op eration

and shall be equipped with following features:

Provided w ith emergency ma nual charging fac ility. The mo tor shall b e

automatically,

(me chanically)

de li nked

once t he

ma nual

c harging

h andle

is

inserted.

Closing operation

of c ircuit

bre aker sl hautomaticallyl

i nitiate

charging

of

the

spring for the next closing operation.

One complete c losing o peration s hall b e c ompleted o nce t he closing impulse is

given and the first device in

the control scheme has responded even though the

control switch / PB is released provided no counter trip impulse is present.

13.3 MICROPROCESSOR BASED RELEASES

13.3.1 GENERAL

The c ontrol unit shall be interchangeable on s ite for adaptation to c hanges in t he

installation.

Sensors shall b

e

non-magnetic or

of th e

Ro

gosky type

for

accurate

c urren

measurements.

The control unit shall measure the true RMS value of the current.

The control unit shall comprise a th ermal memory to store temperature-rise data in the

event of repeated overloads or earth faults. It shall be possible to disable this function if

necessary.

13.3.2 PROTECTION

The control unit shall offer the following protection functions as standard: Long-

time (LT) protection with an adjustable current setting and time delay; Short-

time (ST) protection with an adjustable pick-up and time delay; Instantaneous

(INST) protection with an adjustable pick-up and an OFF position. Earth-fault

protection with an adjustable pick-up and time delay.



Current and time-delay settings shall be indicated in amperes and seconds respectively

on a digital display. Acknowledgement that the setting change should translate to the trip

threshold.

13.3.3 MEASUREMENTS

An ammeter with a digital display shall indicate the true RMS values of the currents for

each phase.

An LCD Screen should continuously display the most heavily loaded phase apart from the

load level on the three phases.

A maximeter shall store in memory and display the maximum current value observed since the

la st r eset. The da ta s hall c ontinue t o b e stored and displayed e ven after opening of the

circuit breaker.

The control unit shall measure voltages and calculate power and energy values.

These v alues s hall be d isplayable o n t he sc reen and updated ev ery second. The minimum

and maximum values shall be stored in memory.

13.3.4 COMMUNICATION

The circuit breaker shall be capable of communicating the following data through a bus:

Circuit-breaker s tatus (op en/closed, c onnected/disconnected/test, trip ped on a fau lt,

ready to close)

Control-unit settings, including protection setting

parameters. Tripping causes

The measurements processed by the control unit: cur rent, voltage, frequency & power

active & reactive).

It shall be possible to remotely modify circuit-breaker settings:

Settings within the range defined by the switches on the front panel of the control

unit; Settings of the protection functions and the alarms.

It shall be possible to remotely control the circuit breaker of identified feeders only.(Viz. all

incomers & bus couplers)



Communications functions shall be independent of the control unit.

13.4 BREAKER HANDLING TROLLEY

Trolley for transportation / replacement / handling of the circuit breaker- 1 No for each

switchboard shall be supplied, The trolley shall have an arrangement of lifting / lowering

of the t rolley platform with a gear operated handle and s elf l ocking p rovision at th e desired

level with the help of a ratchet.

14. FUSE SWITCH MODULES

Fuse switch modules shall be fully drawn out type.

Fuse switch modules shall be provided with components, as specified. The module shall

comprise of the following:

Feeder switch with TP/TPN/FP with HRC fuses and neutral

link Set of cluster type LED lamps for ON / OFF

Meters & transducers, asspecified Current transformers

Terminal blocks, interconnection bars / wires, ferrules, etc. as per requirement

The switch modules shall have doors made out of 1.6 mm steel or heavier. Doors shall be

mounted on adjustable and removable pin type concealed hinges and so arranged that

unit doors may be removed without disturbing the unit doors above or below.

The switch operating handles shall be capable of being padlocked in the 'OFF position.

For the purpose of standardization, similar components in th e switch board shall be of the

same make / brand identical and interchangeable.

Only the operating handle of the load break switch shall be accessible for operation with

the related door closed.

The doors shall be i nterlocked with the associated load break switch so that the door can be

ope ned only when the switch is in the de-energized (off) position and the doors shall not be

capable o f being c losed with th e s witch in t he en ergized ( on) po sition. Provision shall also

be available to defeat the interlock.

Each compartment shall have suitable name plate which shall be f ixed on the cover in

distinct colour to designate the feeder number, feeder designation, current rating & HP /

kW of the related equipment.



15. MOTOR FEEDER STARTER MODULES

Types of starters for various ratings & applications shall be as below:

Motors

--- Direct online (DOL)/Soft starter

Valve --- Reversible DOL (RDOL)

Lighting panels/heaters --- Feeders with MCCB/switch fuse unit

The s tarter modules s hall be of a pproved quality a nd mak e and c omprise of t he

following:

Starter module shall be fully drawn out type.

Feeder switch with 3 poles with HRC fuses /MCCB/ ACB, as applicable

Air-break contactor(s)

Bi-metallic over load relay

HRC fuses for the control circuits.

Selector switch,

Set of cluster type LED lamps equipped with Low Voltage Glow Protection for ON /

OFF / TRIP. OPENED / CL OSED lamps shall b e made a vailable additionally fo

valve feeders.

Set of pilot devices comprising of Oil tight 'RESET' button complete with actuator and

necessary linkages.

Meters & transducers,

Current transformers for metering and protection

Terminal blocks, interconnection bars / wires, ferrules, etc. as per requirement

The starter modules shall have doors made out of 1 .6 mm steel or heavier. Doors shall be

mounted on adjustable and removable pin type concealed hinges and so arranged that

unit doors may be removed without disturbing the unit doors above or below.

Only the operating handle of the load breakswitch set, an d the RESET push buttons

shall be accessible for operation with the related doors closed.



The fuse ratings in the load-break switch fuse units/MCCB and over load relays shall be

suitably c oordinated with the mai n c ontactor ratin g to meet typ e '2' re quirements in

accordance with IS:13947. The selected switch ratings at AC23B duty shall be not less than

the corresponding fuse/MCCB rating, in all the cases.

Following colour coding to be used for panel wiring:

Power Circuit - Red / Yellow / Blue / Black

(Alternatively black with colour coding

sleeve.) AC control wire - Grey colour

DC control wire - White

Earth wire - Green

16. MINIATURE CIRCUIT BREAKERS AND MCCBS

MCBs shall be used in all the AC control circuits and DC c ontrol & lighting feeders, as

specified. However, control fuses may be used in the ACB feeders for DC circuit.

The MCBs sha ll be s uitable fo r manual c losing a nd o pening and automatic trip ping

under o verload

and s hort c ircuit

c onditions.

They

s hall op erate

on “Hammer

Tr ip”

principle. They shall be provided with trip-free mechanism.

The minimum s hort circuit breaking c apacity of

MCBs

shall b e 9KA r .m.s. at 0.55

p. .

The c ontractor s hall b e r esponsible to check an d coordinate the

MCB c haracteristics

with the back up fuse provided in the LDB.

The M CBs shall

be s uitable f or housing in the lightin g p anels

and f or c onnection of

standard copper / alumini um wires at both the incoming and outgoing ends by c opper

lugs or bus bars connection on the incoming end.

The terminals of MCB and ON and OFF positions shall be clearly and indelibly marked.

The MCBs shall generally conform to IS: 13947.

All MCCBs should have over load, short circuit element and earth fault protection that can

be adjusted by knob.

17. FUSES

All fuses shall be of high rupturing capacity (HRC) cartridge plug-in type conforming to

IS:13703 IEC:269, Part 1, Part 2. No bolted type fuse shall be used.



Motor fuse characteristics and ratings shall be chosen so as to ride over starting period

and not operate during motor starting. They shall also not operate before the associated

motor thermal overload relay for 1.1 times the motor starting current. Fuse rating shall not

exceed associated switch rating.

Design of fuse mounting arrangement shall be such that it can be replaced with the help

of fuse puller even when the circuit is live.

Fuse ratings finally chosen for application in various circuits shall be subject to Owner‟s

/ Consultants approval.

Non-hygroscopic ins ulating bar riers prefera bly of FRP o r s imilar materi al s hall be provided

between power fuses.

18. CONTACTORS

The contactors shall be air break type, equipped with three main contacts and minimum

2 NO + 2 NC auxiliary contacts. The main contacts of a particular contactor shall have

AC 3 r atings for general AC mo tor cir cuits, AC5a fo r AC ligh ting circu its, AC6b for

switching of capacitor banks and DC6 for DC lighting circuits, AC4 for bidirectional motor

inching facility, as per IS:13947.

The auxiliary contacts shall be rated for minimum 5 Amps at 240 V AC and 220V DC.

Unless specified otherwise, the coil of the c ontactor shall be suitable for operation on 240V

AC s upply and s hall work s atisfactorily bet ween +l0 % a nd - 15% of th e r ated voltage.

The contactor drop-off voltage shall be between 45% to 65% of the rated coil voltage.

Auxiliary c ontactors s hall generally be used for i nterlocking and mult iplying c ontacts.

Auxiliary contacts shall be capable of c arrying the maximum estimated current, but not less

than 5A at 240V AC.



Contactors shall not dropout when a fault occurs on an adjacent feeder.

All motor feeders shall be provided with auxiliary contactors as needed and to provide

adequate number of spare contacts.

The contacts of the auxiliary contactors and the auxiliary contacts of the main contactor shall

be rated for mak ing, carrying a nd b reaking 10A, 24 0V AC and 1 A, 2 20V DC (inductive

circuit). All spare contacts shall be independently wired to the terminal blocks.

Contactor c oil mo unting a rrangement shall be s uch tha t its rep lacement is possible

without disturbing any wiring connection.

Contactor shall be capable of closing on system prospective symmetrical fault c urrent

when backed up by the large HRC fuses appropriate to the rating of the contactor.

Reversing contactors s hould be provided with ele ctrical a nd me chanical inte rlocks between

forward and reverse contactor.

19. OVERLOAD RELAYS (THERMAL) FOR SINGLE PHASE AND

OVERLOAD PROTECTION

Over lo ad relays w ill be of bi -metallic thermal overload type or electronic type a s

specified in the drawings.

Bi-metallic Ov er Load R elay, t hree el ement type d irectly m ounted, front adjustable,

ambient temperature compensated bimetallic devices of suitable range to match with the

rating / o utput of the motors c onnected to the r elated s tarter and c omplete with hand

resetting device. The relays shall be provided with minimum I NO + I NC contacts with a

rating of 5 Amp s at 240 V I PH, 50 HZ AC and 1.3 Amps at 220V DC (Inductive load).

The bi-metallic relays s hall h ave double s lide m echanism f or single phase f ailure

detection

even

at

partial

load conditions. Heav y d uty

r elays

shall be c onsidered,

wherever the starting time is expected to be very high.

The overload relays for all motor and valve feeders shall be three (3) elements positive

acting, a mbient

tem perature

c ompensated, time lag

thermal

bimetallic ty pe with

adjustable settings. Thermal Overload Relay shall be provided with built in single phase

prevention fa cility. Th ey s hall

be h and reset with t he help of p ush b utton and reset



The range of thermal overload relay chosen shall be adjustable to 70 – 110% of full load

current of corresponding motor.

Thermal overload relay shall either have a pair of 1 N/O + 1 N/C potential free contacts or

a set of changeover hand reset type contacts.

20. CURRENT TRANSFORMERS

The current transformers shall be of bar primary wound secondary cast resin type with

copper c oils and hav e a

short t ime

withstand rating equal to tha

t of the as sociated

switchgear for one second. It shall be the responsibility of the vendor to co-ordinate the

burden of the CTs with the ac tual requirements of relays , instruments, leads etc .,

associated with

the

particular CTs. The minim um requi rement s hall

be 10VA bur den,

accuracy class 1.0 and an instrument safety factor of 5. CTs with 0.5 accuracy clause

shall be provided, wherever specified.

The CTs shall be provided with the following:

Test links in both secondary leads to carry out phase angle & current

measurement tests.

Earth link to which the leads of the CTs shall be connected so as to facilitate easy

measurement of Insulation Resistance of the CTs.

Current transformers shall be des igned such as withstand open circuit secondary with

primary rated load for a short duration to be stated in the bid.

CTs s hall have polarity makings i ndelibly marked on e ach tr ansformer at t he l ead

terminations and at the associated terminal block. Facility shall be provided for s hort circuiting

and grounding the CT secondary at th e terminal blocks. Secondary terminals shall be provided

with protective cap.

CT ter minal block s hall be d isconnecting typ e a nd s uitable for round type lu gs with facility

for testing and short circuiting of individual CT.



All CTs shall be provided with supports independent of Busbars / Busbar supports.

The CTs s hall b e located in such a way that t hey c an b e eas ily appr oached fo r maintenance

without necessitating shutdown of adjacent feeders.

21. VOLTAGE TRANSFORMER

Voltage transformers shall be resin cast type with copper coils.

Current limiting HRC fuses shall be provided on the primary and secondary sides of the

VT. Facility for visual indication of rupturing of the fuses shall

preferably be provided. It

shall be possible to r eplace a f use s afely without ha ving to de-energize the m ain

busbars. The voltage transformer and fuses shall be completely disconnected in fully

draw out position.

It should be possible to replace V.T.‟s without having to de-energize the main busbars.

Voltage transformer mounted on breaker carriage is not acceptable.

Sufficient VA ma rgin a nd ter minals s hall be p rovided for c onnection of re mote transducers for

customer‟s DCS system.

Fuse failure relay shall be provided on the s econdary of v oltage transformer to monitor

LV fuses.

22. RELAYS

All protective relays shall be back connected, draw out type, suitable for flush mounting

and fitted with dust tight covers. All relays shall be mounted on the front of the panel and

shall be specified as per requirement. The current and the voltage coils shall be rated as

specified.

All protective relays shall be intelligent microprocessor based numerical type with IEC

61850 communication protocol capabilities &sequence of eve nt/disturbance recorders for

downloading on serial communication to SCADA.

Motor pr otection r elays shall b e o f numeric/microprocessor type w ith self diagnostic

facility, RS 485 communication port with suitable protocol for interfacing with PC / DCS,

software for da ta d ownloading and c onfiguration. Fe eder protection rel ays s hall hav e

IDMT ov er current & e arth fa ult elem ents. Motor protection relays s hall have over



Rated continuous, short time thermal and dynamic currents for coils shall be suitable for

service involved.

Rated continuous making and breaking currents for contacts shall be suitable for service

involved.

AC re lays shall be rated fo r op eration on 1A s econdary c urrent and 110V s econdary

voltage; number and rating of relay contacts shall suit the system requirements.

The Contractor shall furnish, install & co-ordinate all relays to s uit the r equirements of

protection, interlock and bus transfer scheme as broadly indicated in the annexures and

drawings.

23. CONTROL / SELECTOR SWITCHES

Control switches shall be of the heavy duty rotary type with name plates clearly marked

to s how the operation. The y s hall be semi-flushed mounting with only the fr ont plate

operating handle projecting. Circuit breaker control switches shall be of the spring return

to neutral typ e, w hile loc al / MCC / re mote s elector switches an d instrument selector

switches shall be of the stay-put type.

Control and s elector s witches s hall be

rotary

type and provided

with p roperly

designated escutcheon plates c learly marked to s how

operating pos itions.

To ggle

switch shall not be used for such applications.

Switch ratings shall be adequate for the purpose intended but shall not be lower than ten

(10) amperes making and continuous carrying, and breaking ten (10) A, 240V AC and 1A,

220V DC (inductive circuit) or the requisite circuit breaker operating coil currents at 220V

DC.



Circuit breaker control switches shall have required number of electrical ways and three

(3) p ositions ins cribed TRIP / NEUTRAL / CLOS E. The y s hall hav e s pring return to

neutral feature and shall be provided with lost motion device, sequence device and after

close and after trip contacts and pistol grip handle. These shall be Alstom type „ODS‟ or

equivalent.

Local / MCC/ remo te s elector s witch handles s hall be eit her s pade o r

pointer or oval

shaped. These shall have required number of positions and contacts.

All ammeter and voltmeter selector switches shall be four (4) position piano type integral

with the indicating me ters. Amme ter se lector s witches sh all ha ve ma ke before bre ak

type contacts so as to prevent open circuiting of CT secondaries when changing position

of the switch.

24. MARSHALLING COMPARTMENTS

Marshalling compartments /

cabinets, as anextension for

the s witchboards

shall be

provided, for connection of Hardwires from DCS racks.

Transducers and a uxiliary c ontactors of the in dividual m odules o f the s witchboard,

whose outputs are required to be ho oked up for DCS interfacing, shall necessarily be

housed in the marshalling compartment with suitable arrangement of Hard wire scheme.

Marshalling c abinet s hall house terminal ocks,bl apart fro m auxiliary c ontactors a nd

transducers for c onnection to MCC c ompartments / DCS racks Ho wever, lo cal pus h

button station shall be directly connected to the respective motor feeder compartments.

The terminal block arrangement shall be arranged as below.

All digital inputs (DIs) from different feeders to be terminated at a separate array of

terminal blocks.

All digital outputs (DOs) from different feeders to be terminated at a separate array

of terminal blocks.

All analog inputs (AIs) from different feeders to be terminated at a separate array

of terminal blocks.

All terminal blocks shall be identified with the respective feeder name.

All incoming and outg oing motors feeders of LT switchboards shall have provision for

selection of local / remo te (DCS) facilityPotential. free I/O c ontacts f or St art / Stop



command ON, OFF& TRIP and feeder status signals shall be pre-wired and brought to

a common Marshalling chamber for DCS hookup.

All incoming and outgoing feeders of MCC/PMCC shall have spare contacts pre-wired and

brought to MCC DCS Marshalling chamber for status indication & control from DCS.

25. METERS

Energy mete rs s hall b e of elec tronic typwithe cla ss o f a ccuracy 0 .5 o r better. Th e

meters shall be capable of indicating all phase instantaneous parameters and recording

kWH. Th ese should be s uitable for 3 phas e, 4 wire 5 0 Hz

c ircuits

with u nbalanced

loading.

All th e meter s

used

shall be

mic roprocessor bas

ed mu

ltifunction type wi

communication capabilities for downloading on serial communication to SCADA system.

The communication ports of all MFM & composite protection relays shall be integrated in

common data b us with data concentration an d open pr otocol to have soft in terfacing

with plant SCADA system.

Test terminal blocks shall be provided in the circuits, wherever static meter and energy

meters are provided.

The a nalog meters, wherever p rovided, s hall be of flu sh mo unting ty pe with s quare

pattern of size 144mm for incomer feeders and 96mm dial size for outgoing feeders. The

dial shall have black numerals with a white background and the scale / range of meter

shall be such that the rated value is indicated at around 70°.

Ammeters shall be compatible with CTs of 5A secondary and read actual currents. For

motor feeders ammeters shall have suppressed scale upto 6 times of full load current after

1.2 times of full load current and shall have red mark on full load.

26. TERMINAL BLOCKS

The t erminal blocks pro vided i n the sw itchboard sha ll be mounted vertica lly near the

bottom s ide of e ach module unit, in the c able chamber a t a s lightly up ward a ngle, to

provide clear and easy access to the terminals.

Each wire at the terminal blocks shall bear appropriate number / letter ferrules.



Wiring to the door shall be done by flexible cable & the cables shall be bunched, sleeved

and cleated so tha t no m echanical damage can occur to the c ables when t he d oor swings.

Not more than 2 wires shall be terminated at one control terminal.

All terminations s hall b e of adequate current r ating and size to s uit in dividual f eeder

requirements.

All the te rmination ends sha ll be pr ovided w ith ha rdwares like cad mium c oated bolts,

nuts, s pring washers a nd t win br ass washers o f 2mm thick and having an equiv alent

contact area of the terminating lug.

Outgoing po wer termi nations s hall bedsigned PVC alumi nium c ables. Suitab le provision

shall be made for termination of higher size cables.

Each control terminal block shaft has 20% spare terminals.

Inter module wiring in the same panel shall be through vertical cable alley.

The rating of the terminal blocks shall be minimum 10A.

Terminal blocks for all CT/VT connections to be of sliding contact type.

27. CONTROL AND SECONDARY WIRING

All s witchboards and panels shall be supplied c ompletely wired intern ally up to t he terminal

blocks; ready to receive Owner's cable shall be provided by others.

All inter-cubicle a nd inte r-panel w iring and connections b etween pan els of s ame switchboard

including all bus wiring for AC and DC control supplies and annunciation, space heating system

shall be provided by the Bidder.

All inter nal wiring s hall b e c arried out with 11 00 V g rade, s ingle c ore, 2.5 sq. mm or

larger stranded copper wires having colour-coded, PVC insulation. CT circuits shall be wired

with 2.5 square mm copper wires. Voltage grade and insulation shall be same as above.

Extra-flexible wires shall be used for wiring to devices mounted on moving parts such as

hinged doors. The wire bunches fro m the pan el ins ide to the doors s hall be properly

sleeved and cleated.



All wiring shall be properly supported, neatly arranged, readily accessible and securely

connected to equipment terminals and terminal blocks.

Internal terminations of stranded conductors shall be made with solderless crimping type

tinned copper lugs which shall firmly grip the conductor, or an equally secure method.

Similar lu gs s hall also be pr ovided at both ends o f components to c omponent wiring.

Insulating sleeves shall be provided over the exposed parts of lugs.

Engraved core ide ntification fe rrules

marked to c orrespond

with

panel w iring diag ram

shall be

fitted at both

e nds

of

each w ire. The

ferrule

shall be "Nov oflex" typ e

or

equivalent. The wire number shall be in accordance with lS:5578. Red Ferrules should

be provided on trip circuit wiring.

Wiring for equipment w hich may to b e supplied by the O wner a nd fo r w hich the

Contractor has to provide mounting arrangement in his panels, shall also be provided by

the Contractor, upto the terminal blocks.

Spare auxiliary contacts of individual feeder shall be wired up to marshalling rack

All connections within individual m odules rated 10 0 A an d abov e shall be by PV C

covered tinned copper/Aluminium links or fixable connections. The cable connections for

modules le ss than 100 A

sha ll be s elected in such a way t hat t here

will not be any

melting/shorting. In case of a short circuit inside the module, the cable shall have current

rating to carry the let-through energy of the corresponding fuses in case of a fault.

The insulation of the cable and its cross section shall be decided considering the high

ambient temp erature within t he mod ule. F or all modu les where use of c able is

envisaged

by the Co ntractor s pecific ap proval from the

O wner/Consultant

regarding

cable details shall be taken.

27.1 INTER TRIPPING

Provision shall be made for tripping of incomer LT breaker on tripping of upstream HT

breaker. Provision for tripping of upstream HT b reaker on fault tri pping of LT inc omer

breaker shall also be provided.

28. ANNUNCIATION SCHEME

Annunciator shall be static type.

Hooter and bell shall be provided for trip & alarm indication

respectively. Number of points shall be as per list.

Shall have facilities for test, reset and accept.



Shall con sists of annunciation windows,rel ay blocks w arning bell, emerg ency

hooter, push buttons etc.

All windows shall have two bunch LED in parallel.

All accessories including actuator (if respective scheme is in Contractor's scope)

shall be provided.

Sequence of operation shall be as follows :

Description

Audio

Visual

On occurrence of fault ON Flashing

On accepting OFF Steady ON

On resetting (fault cleared) OFF OFF

On resetting (fault persists)

OFF

Steady ON

29. TESTS FOR L.T SWITCHGEARS

29.1 ROUTINE TEST

The tests shall include but not necessarily limited to the following.

Operation under s imulated s ervice c onditions to ens ure accuracy of wiring, correctness

of control scheme and proper functioning of the equipment.

All wiring and current carrying part shall be given appropriate HV test.

Routine test s hall be c arried out o n all equipment su ch a s CBs, switches / fuse

switches units / MCCBs, Contactors, relays, meters etc. Routine test shall include

measurement of insulation resistance.

Routine test shall be conducted in accordance to the relevant IS.

29.2 TYPE TEST

The supplier shall submit all type test certificates for verification and approval of owner.

The Owner reserves the right to witness any orall the tests, for which at least fifteen

(15) days of advance notice shall be given by the contractor.

30. MANDATORY SPARE PARTS FOR L.T SWITCHGEARS

The bidder shall supply mandatory spares



31. DRAWINGS, DATA & MANUALS

31.1 TO BE SUBMITTED WITH THE BID

General arrangement drawing showing constructional features, space required in front for

withdrawals, disposition of v arious a ccessories and en try p oints of b us duct/cable etc.

Make, typ e and c atalogue n umber of different equipment an d ac cessories a long with

technical leaflets, data sheets, curves etc.

Type test certificates of similar equipment. In case type test certificates as per IS or IEC of

identical equipment of the offered items are not submitted, the Bidder shall have to

conduct the typ e b est on the o ffered equipm ent befo re delivery free o f charge to the

Owner or Bidder‟s testing charges are to be mentioned.

Bill of materials.

Typical foundation plan.

Typical breaker control schematic, MCC control schematic.

Matching flange & terminals for bus termination.

Calculation of busbar size selection.

31.2 TO BE SUBMITTED FOR APPROVAL AND DISTRIBUTION

Dimensional general arrangement drawings with cross section showing the disposion of

various a ccessories, s pace requirement and

busduct/cable e ntry points for all

switchboards. (A)

Transport/shipping dimensions with weight for each equipment. (A)

Data Sheets. (A)

Cross section with part lists. (R)

Consolidated Bill of Materials. (R)

Drawing showing s pace req uired in fr ont for w ithdrawals and c able entry points o f

SWGR/MCC/DB. (A)

Single line diagram for each board. These are to be developed on the basis of inputs to

be given to the successful Bidder. (A)



Typical Control schematic and wiring diagrams of all SWGR/MCC/DB. (A)

Feeder wise

Control Sc hematics fo r

all boards (b ased on Purchaser‟s b lock logic

diagram/operational write-up to be made available during detail engineering) showing all

external interlocks/hook-ups and connections/ disconnections within the panels that may

be needed to make typical control schemes suitable for any particular drive. (A)

Documents on motor protection relay application c heck with b ack-up c alculation and

relay setting chart. (A)

All relevant equipment data sheet and catalogues. (R)